Sanding, abrading, or polishing machine.



PATENTED 11:13.11, 190s.

W. J. MADDQX.

SANDING, ABRADING, 0R POLISHING MACHINE." .Armculox FILED AUG. 19., 1907.

PATENTBD PEB. 11, 1908'.

W. J. MADDX. SANDING, 'A.BRADING\, OR-POLISHING MACHINE.

APPLICATION Hmm AUG. 1n, 1907.

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No. 878,649. PATBN-TED FEB. 11, 1908. Aw. J. M'ADDOX. l

SANDING, ABRADING, 0R POLISHING MACHINE.

APPLICATION FILED AUG. 19, 1907.

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WILLIAM JUDSON MADDOX, OF .IAMESTOWN NEW YORK.

SANDIN G, ABRADING, OR POLISHING MACHINE.

Speccation of Letters Patent.

Patented Feb. 11, 1908.

Application filed August 19.1907. Serial No. 389,269.

To all whom it may concern: y

Be it known that I, WILLIAM JUDsoN MADDox, of Jamestown, in the county of Chautauqua, State of New York, have invented a certain new and useful Im rovement in Sanding, Abrading, or Po ishing Machines; and I do hereby declare the following to be a full, clear, and exact descri tion of the same, reference being had to tlffe accompanying drawings, forming a part of this specification, and to the figures and letters of reference marked thereon.

This invention relates to machines for sanding, smoothing or polishing plane or substantially lane surfaces, such, for instance, as tab e tops, the invention being more particularly applicable in machines of that ty e wherein an abrading or sanding materia is carried by an endless belt running .on suitable pulleys' and having means for pressing the belt into contact with the work intermediate the supporting pulleys.

In accordance with the present invention the means for pressing the belt into contact with the work is substantially arc shaped or in the form of a rocker with a long radius and mechanical means are employed for oscillating the presser or rocker so as to give a uniform action over a large area while the surface in contact with the belt at any one time is relatively small, such oscillatory movements, however, being under the direct control of the attendant whereby the range of movement, as Well as the center of the arc of oscillatory or rocking motion may be varied at will or as required by the shape or contour of the work.

elevation but with the rocker or belt pressingy member and its supports omitted. Fig. 1s a detail perspective view of the carrying frame shown in elevation in Fig. 5. Fig. 7 is a detail perspective view of the preferred form of rocker shaft and mechanism for Vadjusting the center of the arc of oscillation of the rocker.

Similar letters of reference in the several figures indicate the same parts.

Inasmuch as machines of the type to which the present invention relates and employing an endless abrading belt, are already known, it will not be necessary herein to describe in detail the general construction of the machine further than to say that in the particular machine illustrated the bed composed of parallel members l is supported at the ends on hollow pedestals or legs 2, which. may be suitably secured to the floor. Pulleys or carrying wheels 3 for the endless abrading belt 4 are mounted on shafts 5, journaled in bearings at the ends of the bed. One of the shafts 5 carries fast and loose driving pulleys 6 orpother appropriate driving means, while the other shaft is adjustable bodily by a hand wheel 7 to increase or reduce the tension on the belt and also about a vertical axis by hand wheel 8 to bring the shafts into parallelism, and the pulleys into a coincident plane, these adjustments being Well understood in this type of machine.

Horizontal tracks 9 for a sliding or rolling work support l0 are adjustably mounted on .ways on the inner faces of the pedestals or legs, the adjusting means preferably consisting of vertically arranged screws 11 journaled in the pedestals and having miter gears 12 at the upper ends with which similar but smaller gears 13 on a horizontal shaft 14 mesh. The shaft lis adapted to be turned by a hand wheel 15, whereby the attendant may readily raise and lower the work support and work thereon. The lower reach of the abrading belt passes above and substantially parallel with the top of the work support and in accordance with the present invention, a curved resser. or rocker 16 is employed to press the lielt into contact with the surface of the work on the support. At or near its ends, the rocker 16 is connected by universal joints 17, which permit it to conform to the lane of the face of the work, with the ends ofllever arms 18 pivotally mounted at their proximate ends on a bracket or projection 2O on the front of the bed 1.

The lever arms are provided with slot bearings 21 preferably extending substantially horizontally and adapted for the reception of pins 22 of crank arms 23 on the forward ends of rock shafts 24. The crank arms 23 are connected for simultaneous movement by a link 25, best seen in Fig. 6, said link being bowed downwardly to pass under the bracket 20 as shown and is preferably of such length that the crank pins are closer together than the centers of the rock shafts, with the result that oscillatory movementof the rock shafts will impart a rocking movement to the rocker 16, the relation of the parts and curvature of the rocker being` such that during a full maximum movement each part of the face of the rocker is effective in pressing the belt against the work and hence while but a short section of belt is in contact at any one time the working area may be practically coextensive with the length of the rocker.

By varying the range of movement of the rocker and making the center of movement central of the area ofthe work to be operated on, it will be seen that the attendant has a perfect control, enabling him to dress small or large surfaces without lost motion or to dress slight depressions in the surface without removing an excessive depth of material at the high points, this being especially advantageous in dressing veneer or other thin coverings.

The rocker is operated andA the manual control effected by a link drive, thus a rod 25l connects a crank arm 26 on the right hand rock shaft 24 with a slide 27 working in ways in a cross piece 28 of the frame. The slide 27 is pivotallyand slidably connected with a link 29 by a connection 30 (Fig. 3). The

link 29 is pivotally mounted on a radius bar 31, the radialv position of which is controlled by a rack 32 and screw 33, on a shaft 34, journaled in the frame and having a hand wheel 35, said link being operated by a connecting rod 36 extending from one end of the link to a crank pin 37 preferably mounted in the face of a screw gear 38, mounted on a shaft 39 journaled in the frame and also serving as the axis for the radius rod or bar 31. Gear 38 meshes with a screw or worm 40 on the drive shaft. Obviously, through the manipulation of the hand wheel the link may be set to gear the rock shaft and rocker a long or short stroke or the movement of the rocker may be entirely arrested if the link be moved until its axis coincides with the center of the connection between the link and slide.

The center of the arc of oscillation of the rocker may be most conveniently adjusted by adjusting the relative position of the crank arms on the rock shaft and as shown in detail in Figs. 6 and 7 it will be seen that the hub of the crank arm 26 is journaled on a sleeve 41, slidably mounted on the rock shaft 24. The crank arm is heldeagainst move ment longitudinally of the shaft by a bracket or key 42 entering a groove in the hub of the arm and its angular position with relation to the sleeve is controlled by a spiral slot 43 in the sleeve and a coperating pin 44 in the hub of arm 26. The sleeve is moved longitudinally and its angular relation to the shaft preserved by a transverse slide nut or key j 45, carried by the sleeve and working m a slot 46 in the shaft 24. The shaft is hollow for a portion at least of its length and receives a screw shaft 47 for coperation with the nut slide 45, said screw being held against longitudinal movement by a key 48 or other well known means and having at its end a hand wheel 49 for convenient manual manipulation. With this arrangement the center of the arc of oscillation of the rocker may be shifted to any desired point without stopping the machine.

In the present machine the pressure exerted by the rocker is controlled in a very simple manner by mounting the rock shafts in a supplemental frame 50 hinged at 51 (Fig. 5) to the rear of the main frame or bed and an adjustable stop screw 52 at the front of the supplemental frame adapted to rest on a pivoted incline or cam plate 53 on the bracket 20. Said cam late has a handle 54 whereby the downward limit of movement of the supplemental frame and rocker may be accurately adjusted and regulated in accordance with the work to be done.

The weight of the supplemental frame may be and preferably is counterbalanced in part or to any desired extent by a countert should this be necessary. The face of the v rocker is usually padded and covered with pa er as shown at 57, the ends of the padding being held by clamps 58.

In the operation of the machine it is found that owing to the small area of the belt in contact with the work at any one time the action is uniform over thewhole work, mainly because the dust and grit is carried out of the working area practically as fast as it is formedwhereas with machines having a long area of belt contact the dust and grit accumulates between the surfaces as the belt advances, thereby progressively reducing the abrading action and hence giving defective and unsatisfactory results in that one side of the work is acted on more effectively than the other.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In an abrading machine of the type described, a rocker having a curved surface for pressing the abrading material against the work, and means for oscillating said rocker to shift the position of the area of contact with the work.

2. In an abrading machine of the type described a rocker having a curved surface for pressing the abrading material a ainst the work, means for oscillating said roc er to ,shift the position of the area of contact with the Work and means for varying the range of oscillation of the rocker.

3. In an abrading machine of the type described, an oscillatory rocker having a curved surface forv pressing the abrading material against the Work, means for oscillating the rocker and means for shifting the center of the arc of oscillation of the rocker.

4. In. an abrading machine of the type described, an oscillatory rocker having a curved surface for pressing the abrading material against the Work, means for oscillating the rocker, means for varying the range of oscillation and means for shifting the center of the arc of oscillation of the rocker.

5. In an abrading machine" the combination With the endless abrading belt andmeans for driving the same, of an oscillatory rocker having a curved surface for pressing the belt against the Work and manually operated means controlling the movement of the rocker.

6. In an abrading machine the combination with the endless abrading belt, means for driving the same, and an -oscillatory rocker having a curved surface for pressing the belt against the work, of arms on which said rocker is supported, means for simultaneously moving said arms to simultaneously depress one end and elevate the opposite end of the rocker and means for varying the range of movement of the arms.

7. In an abrading machine the combination with the endless abrading belt, means for driving the same and an oscillatory rocker having a curved surface for pressing the belt against the work, of rock shafts, means for rocking said shafts in unison and crank arms mounted on said shafts in non parallel positions, for oscillating the rocker and), whereby one end of the rocker will'be raised as the other is depressed.

8. In an abrading machine, the combination with the endless abrading belt, means for driving the same and an oscillatory rocker having a curved surface for pressing the belt against the Work, of rock shafts, crank arms on said shafts for oscillating the rocker and means for holding said crank arms in nonparallel position whereby one end of` the rocker will be raised as the other is depressed.

9'. In an abrading machine, the-combination with the endless abrading belt, means for driving the same, and an oscillatory rocker having a curved surface for pressing the belt against the work, of rock shafts, crank arms on said rock shafts for operatin the rocker and a connection between sai crank arms of a lengt-h less than the distance between the axes of the shafts, whereby one end of the rocker willbe elevated as the other end is depressed.

10. In an abrading machine, the combination with the endless abrading belt, means for driving the same and an oscillatory rocker having a curved surface for pressing the belt against the work, of lever arms each pivotally mounted on a fixed axis at one end and pivotally connected with the rocker at the opposite end, rock shafts, crank arms on said rock shafts cooperating with the lever arms for oscillating the rocker and means for rocking therock shafts.

11. In an abrading machine the combination with the endless abrading belt, means for driving the same and an oscillatory rocker having a curved surface for pressing the belt against the work, of a rocker operating mechanism embodying a slide, a link cooperating therewith, a radius bar to which one end of the link isconnected, an operating crank with which the opposite end of the f link is connected and manually operated means for adjusting the link.

12. In an abrading machine the combina tion with the endless abrading belt, means for driving the same and an oscillatory rocker having a curved surface for pressing the belt against the work, o f a rocker operatingmechanism embodying a rockshaft, a crank arm thereon connected with the rocker, a second crank arm on said shaft and means for angularly adjusting said crank arms with relation to each other for shifting the center of the arc of oscillation of the rocker.

13. In an abrading machine, the combination with the endless abrading belt, means for driving the same and an oscillatory rocker having a curved surface for pressing the belt against the Work, of rock shafts having crank arms connected with the ends of the rocker, a hinged frame in which said rock shafts are journazled whereby the rocker may be lifted and means for rocking the rock shafts.

14. In an abrading machine the combination with the endless abrading belt, means for driving the same and" an oscillatory rocker having a curved surface for pressing the belt against the work, of supports for the rocker, universal joints connecting the rocker and its supports and means for oscillating the rocker to shift the field of contact between the belt and work.

WILLIAM JUDSON MADDOX. v Witnesses:

M. LAvEnN CLAPP,

CoRA M. KEMER. v A l 

